This invention relates generally to the apparatus used to electrostatically retain an exposed photopolymer material on a conductive substrate and the method by which such master is picked up and retained. More specifically, it pertains to the use of a flexible web to electrostatically pick-up onto and retain an exposed permanent master on the conductive area of the web during the production of multiple copies.
The permanent master and the flexible web are used as part of a system to repeatedly produce high resolution and high quality images on receiving surfaces. These receiving surfaces can be conductive, such as printed circuit boards, or nonconductive, such as paper or plastic which may be used in color graphic applications.
Conductive receiving surfaces, such as printed circuit boards, have traditionally been produced by individual laminating, exposing, developing, etching and stripping processes where dry film photoresist has been used to produce the conductive wiring patterns. Heretofore, there has been no method or apparatus available to produce a plurality of copies of conductive wiring patterns from a single master copy of the desired wiring pattern utilizing a dry film resist and photo-imaging. There are many factors which have prevented this type of a system from being employed to manufacture multiple copies from a single master.
Similarly, the use of a single master employing a dry film photoresist in conjunction with nonconductive receiving surfaces, such as those used in color graphics, has heretofore not been possible.
The ability to precisely position the master onto a supporting surface and accurately and repeatedly position it on the receiving surface to obtain the necessary tolerances and repeated copies has been a continuing problem. Similarly, the simple attachment of the master to that supporting surface in a manner that does not damage the master has also been a problem.
These problems are solved in the design of the present invention which utilizes a flexible web to electrostatically pick up an exposed master with a permanent latent image thereon for the repeated printing of toner developed copies on receiving surfaces.